Sales is all about negotiating. You are negotiating from the first word out of your lips on a cold call, to the moment that you touch the contract with your customer's wet signature on it.
Whenever you are listening to a prospect tell you about something that they want or complain about a problem that they want you to help solve, do not be too quick to agree.
If you do, you risk losing your leverage.
Here's an example. Let's say that you are selling photocopy machines. Your prospect tells you that he believes his monthly costs for copying are too high.
So far so good - here's a prospect that has a pain that you can sell to. You ask him to tell you why he believes his costs are too high.
Your prospect starts to tell you all of the reasons why he thinks his costs are high, and what he believes the solutions to the problem are. He tells you what sort of new services or equipment and capabilities he needs. He goes on for 5 minutes or more talking about this.
Being a sales professional, you are most likely what we call a "people person". Most people in sales have a high need for approval from other people. We thrive on interaction and strokes from others.
During his 5+ minutes of speaking you are naturally inclined to give verbal and physical cues to encourage him to keep talking. You are unable to just sit there like a wooden statue. You feel a normal need to reciprocate the communication in small but noticeable ways.
With a high need for approval, you are likely to encourage your prospect to continue talking by giving positive verbal and physical cues. As he is speaking you nod your head occasionally, you say things like "Yes", "OK", or "Right". This is where many of us get into trouble.
By using such positive cues, you are subtly telling your prospect that you can solve their problem, or that you can give them what they want. Why is this bad? In our example here, you don't want your prospect to know just yet whether you can solve the problem. You want the focus to stay on him, his problem, and the consequences of it.
If you let on that you can solve it too soon, then you give up your leverage. He "wants" to know whether you can solve his problem.
And once he knows that you can solve his problem, he'll want to know pricing, terms, customer references, etc. The focus will be on you (instead of on him), and you will have lost control of the sales call.
He'll disassociate from his emotions around his problem. It is at this point that the prospect starts to get intellectual, and tries to figure out how to game you, how to get what he wants out of you at the best possible price. You want to keep the focus of the sales call on the prospect and his pain so that you can find out more important information. You want to know what his budget is, what his decision approval process is, and you want to see if he'll make me a reasonable commitment to you if you can solve his problem.
So instead of giving positive cues while he is speaking for 5 minutes about why his copying costs are so high, give neutral cues.
Encourage him to keep speaking by using words and phrases like "continue", "tell me more", "interesting", "wow", and "I hear what you are saying". What you want is to empathize without agreeing. If you agree to soon, then you give something away without getting what you need in return. Practice this anytime you are negotiating with a prospect.
In other words, practice it all of the time.